Apparatus for controlling the volume of flow of fluids



Oct. 14, 1941. H. E. T. HAULTAIN 2,258,758

APPARATUS FOR CONTROLLING THE VOLUME OF FLOW OF FLUIDS Filed April 10,1939 [Lid-IIIlnllllluhllllllllllllll' I H. E. T. Hau lTa-in PatentedOct. 14, 1941 APPARATUS FOR. CONTROLLING THE VOL- UME OF FLOW OF FLUIDSv Herbert E. T. Haultain, Toronto, Ontario, Canada Application April 10,1939, Serial No. 267,007

2 Claims.

This application is in part a continuation of my co-pending applicationSerial No. 80,947, filed May 21, 1936, which matured into Patent No.2,168,207 issuedAug. 1, 1939.

This invention relates to apparatus for obtaining a constant volume offlow of a fluid and is particularly adapted for use with classifyingtubes such as shown in the above mentioned parent application and myobject is to devise simple automatic apparatus of this character whichis inexpensive to manufacture and yet attains excellent results.

I attain my object by the constructions which may be briefly describedas follows. A fluid supply pipe or line is provided with a reliefopening and an apertured partition. The difference of pressure onopposite sides of the partition is maintained substantially constant byutilizing any variations in said difference to vary the leakage throughthe relief opening, and thus the volume of the flow of fluid through theoutlet end of the supply pipe is maintained substantially constant.

The constructions are hereinafter more fully described and areillustrated in the accompanying drawing which is a diagrammatic view ofmy volume control apparatus.

In the drawing like numerals of reference indicate corresponding partsin the figure.

A fluid supply pipe which may be formed of pieces of tubing 25, 25 and25 is connected with a suitable source (not shown) of compressed air.The piece of tubing 25 is provided with a relief opening 38 at the endof the stem thereof. The leakage through said opening is varied by avalve plug or ball 39 carried by an arm 3|. The ball rests on the uppersurface of thearm which is provided with any suitable means, lying flaton said surface, adapted to limit the movement of the ball relative toits seat formed by the opening 38 so that as the ball is raised by thearm it will center itself relative to the relief opening. When theapparatus is in operation, there is a continuous leakage past the ball.

The arm 3| is pivoted at 32 on any suitable stationary part and isactuated by expansible devices, which in the drawing are shown asbellows 28, 29. These devices are carried one above the other on asuitable stationary frame and each engages a side of the arm 3|. Thepivoted arm 3| is thus passed between the devices. The sides of thedevices remote from the arm engage the upper and lower sides of theframe. One end of each device 28, 29 is closed the other ends of thedevices are connected by flexible tubing 28 and 29 with the fluid supplypipe at opposite sides of a partition 26 therein. The partition may belocated in an expanded passage 26 of the supply pipe and has a smallaperture or orifice 26*- therein. Normally the pressure in the supplypipe at one side of the partition is greater than that at the other sidethereof. of the passage 26 is connected with the upper device 28, andthe normally low pressure side of the passage is connected with thelower device 29 whereby the ball 39 is normally positioned, as set, toeffect the desired leakage under normal condition.

The initial setting of the ball relative to the relief opening iseffected by turning a spindle 40 on which one end of a flexible cord 40*is wound. Intermediate the ends of the cord is connected a spring 40 andthe other end of the cord is secured to the arm 3|. The Weight of thelatter and of the ball is thus counter-- balanced. The inflow to thetubing 25 and the relief opening 38 must be just sufliciently' toprovide a leak at the relief opening when approximately sufficient fluidis flowing through the outlet tubing 25 before the tension of the spring40 is adjusted to obtain the desired normal working leakage at therelief opening. Preferably I provide a valve 25 for varying the abovementioned inflow so that it may be limited whereby a slight variation inthe leakage past the ball 39 will have a materially greater effect invarying the pressure in the tubing 25 than if the said inflow wereunrestricted.

It is obvious that by varying the tension of the spring 40, the volumeof the flow of the fluid escaping through the outlet 38 may be varied tothus vary the difference of pressure at opposite sides of the orifice 26to any predetermined amount.

Any variation in the back pressure in the low pressure end of thepassage 26 which will cause a variation in the differential pressure atopposite sides of the partition 26' will result in the ball 39 beingmoved closer to or further from the relief opening 38 to vary theleakage. Thus the greater the back pressure in the low pressure end ofthe passage 26, the less the leakage at the relief opening 38, and thusthe more the pressure in the high pressure end of the passage will beincreased to maintain a substantially constant difference of pressure atopposite sides of the partition. Immediately the back pressure and isreduced the pressure at the high pressure end The normally high pressureside of the passage 26 is also reduced, to maintain the difference ofpressures at opposite sides of the orifice substantially constant andthus maintain the volume of the flow of the fluid through the outlet 25*substantially constant.

Preferably the pieces of flexible tubing 28 29 are provided with shortlengths of glass tubes 28*, 29 having small bores which tend to dampenany sudden flow of air through the pieces of tubing and thus smoothlyeffect the movements of the arm 3| by the expansion and contraction ofthe devices 28, 29.

The orifice meter referred to in the above mentioned application isshown complete with two indicators 4|, 42, and the supply pipe 25 isprovided with a pressure regulating and safety valve 43 and with ashut-off valve 44.

A pressure gauge 45 may also be connected with the supply pipe betweenthe shut-off valve 44 and the regulating valve 43. and 45 are positionedbetwen the valve 25 and the source of supply. The regulating and safetyvalve 43 is preferably of the same type as the relief valve 39 and itpermits a continuous leak past the ball of the valve 43 to maintain asub- All these parts 43, 44.

stantially constant pressure of the fluid between spindle for windingthe cord is provided for this purpose.

It will be noted that the bellows 29 is located farther from the pivot32 than the bellows 28 to compensate for the pressure of the fluid onthe ball 39.

The indicators 4| and 42 are shown as manometers connected with thetubing 28 29 respectively to indicate the pressures on the oppositesides of the orifice partition 26 eter 4| may be used as a guide duringthe adjustment of the valves 43 and and of the spring to set the valve39 in its initial position.

The volume control apparatus may be used in connection with a device forclassifying finely granulated solids according to size. The con- Themanomstruction and operation of such device is clearly disclosed in myabove mentioned application and in my U. S. Patent No. 2,034,185 issuedMarch 17, 1936, and therefore it is not necessary to describe theclassifying apparatus here except to state that it is most important tohave the fluid flowing therethrough maintained at a substantiallyconstant volume.

What I claim as my invention is:

1. Apparatus for controlling the volume of flow of a fluid including afluid supply pipe having a relief opening and a valve for controllingthe flow through said pipe; a valve for varying the leakage through therelief opening, the pipe being provided with an apertured partition; apivoted arm for actuating the leakage varying valve; means controlled bythe difference in pressure on opposite sides of the partition foractuating the arm, the said means including expansible devices engagingopposite sides of the arm, the expansible device for moving the arm andthus the leakage varying valve towards the relief opening beingpositioned farther from the pivot of the pivoted arm than the otherexpansible device; and an automatic pressure regulating valve having acontinuous leak positioned in the supply pipe at the side of the saidflow controlling valve remote from the apertured partition and therelief opening.

2. A differential pressure operated device comprising a valve member forvarying leakage through a relief opening; a pivoted arm for moving thevalve member towards and away from the opening, the pressure of fluid onthe valve member tending to move the latter to an open position; andhollow expansible devices connectible with sources of differentpressures engaging opposite sides of the arm, one of said devices beingadapted when expanded to cause the valve member to move in a directionaway from the relief opening, the other of said devices being adaptedwhen expanded to cause the valve member to move in the oppositedirection, the last mentioned device being positioned farther from thepivot of the pivoted arm than the first device.

HERBERT E. T. HAULTAIN.

